The iPhone 5 was a significant upgrade to the iPhone line, with a 4-inch screen (up from 3.5), and featuring the lightning connector. The iPhone 5 supports the latest iOS; however, note that there can be issues with using certain Mac OS's with certain iOS's. We recommend talking to a PowerMax representative if you're unclear as to how well the two OS's you plan on using will "get along." We also recommend that you don't automatically upgrade any OS without understanding the potential consequences. Apple provides regular reminders to "upgrade for free," but doing so can sometimes cause problems. Fortunately, the Apple experts at PowerMax are always available and happy to help!

iPhone 5 specifications:

Maximum OS: Latest available

iTunes Version iTunes: 10.7 or later

System Requirements: Mac OS X v10.6.8 or later (note: you cannot sync an iPhone with 10.6.8 or ealier and iOS 9), or Windows 7; Windows Vista; or Windows XP Home or Professional with Service Pack 3 or later

Weight: 3.95 ounces

Display Resolution: 1136 by 640 pixels (326 ppi)

Processor Speed: 1.3 GHz

Built-in RAM: 1 GB

Cameras: 8.0 megapixels (rear), 1.2 megapixels (front)

Connection: Lightning connector

What is CDMA vs. GSM?

There are two basic technologies inside mobile phones: CDMA and GSM. In the United States, GSM is used by AT&T and T-Mobile. CDMA is used by Sprint, U.S. Cellular, and Verizon. Most of the rest of the world uses GSM, which is part of the reason why AT&T phones have been more popular overall: they can essentially be used worldwide just by popping out the sim and putting another one in.

In general, once a phone is registered as a Sprint phone, it's best just to keep that phone with that carrier due to Sprint's strict unlocking policies. The iPhone 5s, 5c, 6, and up can all be used on AT&T, T-Mobile, and Verizon. On iPhone 5 and earlier (and any Sprint phone), you should buy a phone that has the same the carrier listed that you plan on using.

Keep in mind that when you buy a used iPhone, you'll still need to communicate with your carrier to get the phone activated on their network. Note that iPhones are shipped from PowerMax without any SIM card. AT&T SIMs can be purchased from us at the same time as your phone; for other phones, you will need to get a SIM from them and activate it accordingly, and may necessitate a visit to one of their outlets.

We guarantee that our iPhones are genuine Apple iPhones and are available for phone contract. This is important, because with services like "Find My iPhone" and other carrier theft prevention schemes, buying a phone from someone you don't know and may not be able to return can be a real problem. We also offer a 90-day warranty covering the basic operation of the phone.